I have a 2001 GP gt, been having this problem for about a year now, first I lost od in tranny thought it was that, but after I got the $ and tranny fixed it still presists, so here we go. When driving at highway speed the car will suddenly decelerate briefly and then accelerate and you never move your foot on the gas pedal, does it at varieing times usually about every 10 or 15 miles, changed plugs & wires, fuel filter, speed control sensor, the only other thing I can think of is abs sensor, the light is on , got to be from left wheel cause i changed the left one, but what i can find the abs should have nothing to do with this problem and since it cost about 300.00 for a wheel bearing assembly, hoping someone here can shed some light on the subject, thanks guys, any ideas